Catalytic Performance and Steady-State Kinetics of Cu-ZSM-5 for Selective Catalytic Reduction of NO with NH_3

A series of Cu-ZSM-5 catalysts with different Cu loadings were prepared by an incipient wetness impregnation method.These catalysts were used for studies of selective catalytic reduction(SCR)of NO by NH 3.The results showed that Cu-ZSM-5 with 5%Cu loading showed the best catalytic activity,the conversion of NO was more than 80%over the temperature range 198-470℃,and the highest NO conversion was 96.5%.The SCR activity was only influenced slightly by the addition of H 2 O or SO 2.Visible diffraction of the CuO phase was observed when the Cu content was above 5%.The results of steady-state kinetics studies indicated that the SCR reaction over Cu-ZSM-5 with 5%Cu loading was zero-order with respect to NH 3,first-order with respect to NO,and nearly half-order with respect to O 2.The apparent activation energy for the reaction was found to be 47.7 kJ·mol-1.